Trump threatens a global trade war. Europe must unleash a radical alternative | Gabriel Zucman

Unlike tariffs, a new form of protectionism could target climate-wrecking, untaxed corporations and their billionaire owners

• Gabriel Zucman is a French economist

How should Europe respond before Donald Trump's policies destabilise the global economy? All countries will soon have to take a stand on the new US president's tariff threats. While a shift away from free trade clearly carries risks, it also presents a valuable opportunity to reimagine our outdated international economic relations - if we can grasp what makes this moment unique.

In many ways, Trump's economic agenda follows the Republican party playbook that dates back to Barry Goldwater's 1964 presidential run, which launched the party's enduring mission to dismantle Roosevelt's New Deal. Trump claims the US was never better off than under William McKinley's presidency (1897-1901), when the federal government, before income tax existed, was pared down to a minimum.

Gabriel Zucman is professor of economics at the Paris School of Economics and Ecole normale superieure - PSL, and founding director of the EU Tax Observatory